This invention relates to carburetion as applicable to internal combustion engines and more particularly to an improved carburetor which accomplishes better atomization of the fuel leading to thorough vaporization and vastly improved intermingling of the fuel and air at their point of juncture in the carburetor bore. The end result is a leaner fuel air mixture producing more power in an internal combustion engine than has previously been possible to attain. At the same time the process makes possible a readily controllable mixture permitting adjustment over a wide range of fuel/air ratios. The latest state of the art in automobile carburetion generally consisted of a butterfly type throttle valve to control air flow, an idle jet, an off idle jet, a main discharge jet and a power jet to meter fuel. In all four of these states fuel was metered in an almost liquid state at a very restricted area in relation to the cross sectional area of the intake air stream resulting in poor dispersion of fuel throughout the entire intake air mass leading to reduced fuel vaporization. Multi-barreled carburetors were resorted to in an effort to increase fuel dispersion by doubling the venturies and reducing the air intake area surrounding each venturi. In addition to these short comings, the various stages involved led to a less than constant fuel flow curve at all the various possible throttle openings moving from one stage to another. One manufacturer attempted to hold metering rod production dimensions to within 1/10,000 of an inch attempting to arrive at specific fuel/air ratios. When you consider that controlling the quantity of fuel to be metered at a fuel/air ratio of 14.57 to 1 by weight is approximately 10,000 to 1, it is apparent why the problem is so difficult to solve. In today's fuel injected engines, computerized microprocessors have improved the fuel metering process and also the complexity. Liquid fuel is injected under pressure and is finely atomized but it still must. vaporize to burn. Vaporization requires time and manifold travel time exhances the opportunity for vaporization. In addition to this, fuel injection introduces bursts of fuel and as a result does not provided a continuous dispersion of fuel in the intake air stream. This invention is the results fo efforts to address such problems.
In the present invention, the conventional carburetor butterfly type throttle valve has been eliminated. It is replaced by a combination of an eliptically shaped cone and a thin walled cylinder. The cone is held stationary in the center of the carburtor bore by a crossbar and a tube extending downward through the center of the cone. The cylinder's inside dimension is approximately the same size as the largest diameter at the cone base. The outside diameter of the cylinder is a close sliding fit in the carburetor bore at a point above the top of the cone so that when the cylinder is moved fully upward, its base clears the top of the cone proivding an air valve controlling air flow through the carburetor. On the base of the cone, a cap is fastened by a screw thread arrangement. Interfacing portions of the cap and cone are hollowed out to form a cavity or pre-mix chamber. Both fuel and air are drawn into this pre-mix chamber by virtue of the reduced pressure in the (intake manifold. 32 finely drilled orifices in the cone cap perimeter provide access to the pre-mix chamber from the carburetor throat. The volume of fuel and air admitted to the pre-mix chamber is controlled by one fuel metering rod and two air metering rods. The fuel metering rod extending centrally upward from the cone cap into the pre-mix chamber and through the fuel metering tube port provides a coarse control of fuel flow into the pre-mix chamber as this port in the base of the fuel metering tube moves upward in unison with the cylinder air valve admitting increasing amounts of fuel in proportion to the increasing amounts of air admitted to the intake manifold by the cylinder air valve. Idle mixture control is accomplished by adjusting a screw thread arrangement on the upper end of the fuel metering tube which varies the position of the fuel metering tube port in relation to the position of the stationary fuel metering rod and also to the position of the cylinder air valve at its idle position. A primary air metering rod also moving in unison with the cylinder air valve progressively admitts more air to the pre-mix chamber as it is withdrawn from a ported tube leading into the pre-mix chamber thereby maintaining a coarse balance of fuel and air admitted to the pre-mix chamber. A secondary air metering rod moving in a ported tube leading into the pre-mix chamber is externally controlled by an electrically operated thermostatic choke unit providing for cold starts and subsequently controlled by an electrically operated solenoid responding to electric current supplied by an electronic circuit which senses voltage changes supplied by an oxygen sensor. The pulsing of the solenoid operating the secondary air metering rod effectively varies the relative air pressure in the pre-mix chamber thereby providing very minute changes of fuel flow into the pre-mix chamber. It is this control of the relative pressure in the pre-mix chamber that makes possible the precise control of the fuel/air ration. With this mixture of fuel and air in the pre-mix chamber, the fuel in effect is blown out through the large number of orifices in the cone base leading from the pre-mix chamber to the carburetor throat in a spray gun nozzle effect providing finely atomized fuel and superb diffusion throughout the entire mass of the intake air stream as it passes through the carburetor throat. A conventional carburetor float bowl provides a source of fuel and also includes an accelerating pump to insure fuel enrichment for rapid throttle openings. An additional benefit of the cylinder cone air valve combination is that it eliminates atmospheric pressure on moving mechanical components of this carburetor resulting in less wear through use. Accordingly, it is the preferred objective of this invention to provide an improved carburetor that is more economical in the use of fuel, less expensive to manufacture, simpler to service providing equal or better performance than available from the current state of the art. Other objective and advantages of this invention will become apparent from the following detailed description with references being made to accompanying drawings,